(2)在查询下方单击“Expression”。 (3)在操作字段中,选择要编写的表达式类型。 (4)写入表达式。 (5)单击“Apply”。 特殊情况 当查询的数据源没有返回序列或数字时,表达式引擎会返回 NoData。例如,如果一个请求包含两个通过表达式合并的数据源查询,如果其中至少一个数据源查询返回 NoData,那么整个查询返回的结果...
Create an expression for Query C Math operation, ${B}/${A} This will show 0.25, as you would expect. Next, delete the value 5 under Query B, so it does not have data. Queries B and C will disappear, which we don't want. If you change the No value config setting to 0, nothin...
Expression E and C reduce these two series by using the 'last'-function. Now I want to trigger an alert, when C gets bigger than E (when the current connections number gets bigger than the limit). But unfortunately the Math Expression D does not work correctly. It simply shows "No dat...
Using a regular expression Manually selecting included fields Using a dashboard variable Use a regular expression When you filter using a regular expression, field names that match the regular expression are included. For example, from the input data: ...
This transformation is very useful if your data source does not natively filter by values. You might also use this to narrow values to display if you are using a shared query. The available conditions for all fields are: Regex - Match a regex expression. Is Null - Match if the value is...
- **Alerting:** Exclude expression refIDs from NoData state. [#72219](https://github.com/grafana/grafana/issues/72219), [@yuri-tceretian](https://github.com/yuri-tceretian) - **Alerting:** Fix state manager to not keep datasource_uid and ref_id labels in state after Error. [#7...
- **Alerting:** Always show expression warnings and errors. [#74839](https://github.com/grafana/grafana/issues/74839), [@gillesdemey](https://github.com/gillesdemey) - **Tempo:** Added spss config - spans per span set. [#74832](https://github.com/grafana/grafana/issues/74832), ...
在进行了 Reduce 操作之后,新增一个 expression,选择 Math 操作符,进行布尔运算,如下所示: $B>80表示若表达式B返回的结果大于80,返回1,否则返回0。引用其他表达式或者查询的结果时,要使用一个'$'符号,比如,引用B表达式的结果,用'$B'表示。
SSE: Fix math expression to support NoData results. #61721, @yuri-tceretian Security: Fix XSS in runbook URL. #59540, @dsotirakis TimeSeries: Better y-axis ticks for IEC units. #59984, @leeoniya TimeSeries: Fix rendering when zooming to time ranges between datapoints. #59444, @lee...
For more information about how Grafana Alerting processes NoData results, see Configure Grafana managed alert rules. In the case of using an expression on multiple queries, the expression engine requires that all of the queries return an identical timestamp. For example, if using math to combine...